Lack of association between NCAM1 and early onset schizophrenia in a family based study in Shandong peninsula of China.

The neural cell adhesion molecule (NCAM1) gene plays important roles in cellular migration, synaptic integrity and neurodevelopment. Multiple NCAM1 proteins are differentially altered in schizophrenia (SZ). A whole genome association study was first carried out on Affymetrix genome-wide human single-nucleotide polymorphism (SNP) Array 6.0 and two pooled DNA samples consisting of 89 early onset SZ (EOS) cases and 1,000 controls. Association between rs10891495 and EOS was detected (χ(2) = 2 3.66, P = 1.15E-06). The position of this SNP is just within the NCAM1 gene. Since several previous studies reported that NCAM1 was a candidate gene for SZ, we further performed a family based association study and genotyped six SNPs (rs10891495, rs1245133, rs1821693, rs686050, rs12794326, rs674246) within NCAM1 gene in 100 EOS nuclear families. We found no evidence for association with SZ status either for SNP or for haplotype. Therefore, the NCAM1 gene is unlikely to play a major role in the etiology of early-onset SZ in the Chinese population.